Transhalogenation reactions of Halon/Diesel mixtures under extreme conditions

The feeding of a running Diesel engine with the fire extinguishing agents CF 2ClBr (Halon 1211) and CF 3Br (Halon 1301) resulted in the formation of numerous halogenated organic compounds. Flue gas particles were separated by an appropriate filter. The organic gases were collected on modified charcoal and sorbing polymers. Thermodesorption (TD) was the analytical method of choice. When using a Flame-Ionisation-Detector (FID) the gaschromatograms showed a significantly better combustion in case of the halon loaded flue gases than the blanks. Several new peaks were found in the chromatograms obtained from analysis with an Electron-Capture-Detector (ECD) after halon application. Mass spectrometry of TD-gaschromatograms lead to the identification of several volatile halogenated species. Mass balance showed unreacted halomethanes (1211: 65%; 1301:45%) and small amounts of inorganic halogenides (for fluoride based on total input: 1301 7%; 1211 2.5%).